be as careful as possible to get rid of the mold and rinse ur plant with clean water, then pot it in fresh soil, and try live sphagnum on top. and no more misting, humid conditions, or overtop watering
Can you give a little bit more info on the growing conditions of your plant? Type of container you're growing it in, type of water you're using, soil mix, amount and kind of lighting, indoor or outdoor?
Most often mold is caused my very wet, warm conditions with little air circulation. VFTs don't need real humid conditions so it isn't necessary to keep it covered or enclosed. They need good air circulation. Covering it shouldn't affect how it attracts bugs. Flytraps catch bugs whenever conditions are right and the timing of the trap closing is right. Sometimes a trap will be feeding and sometimes it takes a while before it catches anything. You just have to let nature take its course.
Provide a little more specific info and maybe we can help you out. My recommendation...don't cover it!